themox
Aquarium Advice Activist
In my experience with it, it was leaks that did it. I tested by putting it all underwater and blowing through the pipes to see where and if any air bubbles came out. Sure enough, around the lids; even if you drill smaller holes than the tubing.
Once that's done, if you follow the cookie cutter recipe, it should be slowly starting to bubble in about 2-3 hours but the pressure isn't huge so it takes a good while for it to force all the water out of the tubing and then for it to eventually be strong enough to bubble into your tank. I was getting about 1 bubble per second, but mine was inserted into the input of my internal filter so I can't tell you about your diffusion method.
Once that's done, if you follow the cookie cutter recipe, it should be slowly starting to bubble in about 2-3 hours but the pressure isn't huge so it takes a good while for it to force all the water out of the tubing and then for it to eventually be strong enough to bubble into your tank. I was getting about 1 bubble per second, but mine was inserted into the input of my internal filter so I can't tell you about your diffusion method.
